Although one’s attention is apt to be absorbed by the great ships of the first battle line, the ultimate Fount of naval Power, a Navy which built only vast battleships and cruisers would be quite unable to control the seas. A navy’s daily work does not consist of battles. For the main purposes of watching the seas, hunting submarines, blockading an enemy, and guarding the communications of ourselves and our Allies, and also for protecting our big ships against submarines and other mosquito attacks, we needed vast numbers of light cruisers, patrol boats, destroyers, armed merchant cruisers, steam drifters and so on, and these had to be built or adapted with as great an energy as that devoted to turning out the monsters of the first battle line. The construction of light cruisers and destroyers—the cavalry of the seas—kept pace during 1915 and 1916 with that of the big fighting ships, while the turning out of the light fast craft essential for hunting down enemy submarines, far surpassed in speed and other building operations. At the beginning of the war we had 270 light mosquito vessels; at the end of 1917 we had 3,500! Nothing like the tremendous activity in warship building during 1915 has ever been seen in our country. Mercantile building was to a large extent suspended, labour was both scarce and dear, builders could not complete commercial contracts at the prices named in them, the great yards became “controlled establishments” with priority claims both for labour and material. Consequently every yard which could add to the Navy’s strength, whether in super-battleships or cruisers, destroyers or in the humble mine sweeper, were put on to war work. The Clyde, typical of the shipbuilding rivers, was a forest of scaffolding poles from Fairfield to Greenock within which huge rusty hulls—to the unaccustomed eye very unlike new vessels—grew from day to day in the open almost with the speed of mushrooms. A trip down the teeming river became one of the sights of the city on the Clyde and, though precautions were taken to exclude aliens, the Germans must have known with some approach to accuracy the numbers and nature of the craft which were under construction. What was going on in the Clyde during that year of supreme activity, when naval brains were unhampered by Parliament or the Treasury, was also going on in the Tyne, at Barrow and Birkenhead, in the Royal Dockyards—everywhere day and night the Navy was growing at a speed fully three times as great as in any year in our history. * * * * *